WASHINGTON
— Time isn't easing concerns over the enhanced law-enforcement powers of the USA Patriot Act, judging by the debate that's firing up on Capitol Hill over the renewal of its expiring provisions.

President Bush calls the Patriot Act an invaluable tool in the war on terror, but, until this week, little was known about where, why, or how often the law has been applied.

At the same time, confusion persists over what the law actually does. Critics sometimes conflate Patriot Act provisions with other controversial moves, such as indefinite detentions at Guantánamo Bay, Cuba, that have nothing to do with the act. Last week, Montana became the fifth state to pass a resolution critical of the Act. Since 2001, more than 375 local governments have passed resolutions criticizing the law or declaring "civil liberties safe zones" in a bid to discourage cooperation with the law.

But few cases of actual abuse of the law have surfaced. No one, for example, has come forward to claim the compensation provided in the law for abuse of civil rights. One reason, critics say, is that the most invasive powers of the Patriot Act are exercised secretly, some accompanied with gag orders. That means that a librarian, for example, who discloses a request for records under the Patriot Act could be subject to criminal prosecution.

"For these reasons, it has been extremely difficult to uncover information about how the Patriot Act has been used, and even information about whether particular sections have been used at all," wrote Anthony Romero, director of the American Civil Liberties Union, in an April 5 letter to Sen. Dianne Feinstein (D) of California, a member of the Senate Judiciary Committee.

New insights into law's use

On Monday, a day before Senate oversight hearings on the Patriot Act, the Justice Department released some of this information for the first time: Roving wiretaps have been used 49 times under the law. The law's new powers to seize personal records have been used 35 times, none involving medical, library, bookstore, or gun sale records. And delayed-notification search warrants, dubbed "sneak and peek" by critics, have been used 155 times (this doesn't expire at year-end, as Congress demanded for the most controversial provisions).

The new information, while answering some questions, has raised others.

As recently as September 2003, then-Attorney General Ashcroft told Congress that the personal records provision had never been used at all, prompting questions from lawmakers on why it's apparently been used 35 times since then.

And, in an exchange with Sen. Jeff Sessions (R) of Alabama, FBI director Robert Mueller said that one reason federal officials had not had to invoke the law to gain access to library records is that "we have had the cooperation of the libraries to date." The comment caught the attention of a representative from the American Library Association, present at Tuesday's Senate hearing.

"It's a core principle of our profession that user records are confidential. If you're not free to read and research and think, you don't have freedom of speech," says Patrice McDermott, deputy director of the ALA's Washington office, which is conducting a nationwide survey of public libraries on their involvement with law enforcement.

In his first appearance before Congress since taking over the Justice Department, Attorney General Gonzales signaled more openness to revising the law than his predecessor, John Ashcroft, who often said that bids to curb the law would weaken the war on terrorism and endanger American lives.

Still, when pressed by Senate Judiciary chairman Arlen Specter on whether he would be willing to exclude authority to obtain library and medical records from the law, Gonzales declined: "It's comparable to a police officer who carries a gun for 15 years and never draws it. Does that mean that for the next five years he should not have that weapon because he had never used it?" he said Tuesday.

Patriot Act powers set to expire have been used to convict an Imperial Wizard of the Ku Klux Klan who tried to purchase hand grenades to bomb abortion clinics, to trace a threat to burn down an Islamic Center in El Paso, Texas, to dismantle a terror cell in Portland, Ore., and to rescue ababy after its mother was murdered in Missouri, the Justice Department says.

But critics say this is only a partial list of how powers have been used, and that many are unrelated to the Patriot Act's objective of fighting terrorism. More comprehensive public disclosure of how the law has been applied is needed to assess its impact, they say. For example, The ACLU is asking Congress to make public how the Patriot Act was used to conduct a secret search of the home of Oregon attorney Brandon Mayfield, wrongly suspected of involvement in the Madrid bombings. "By lowering the standard of a FISA search, the Patriot Act made it much more likely that mistakes like the one made in the Brandon Mayfield case would occur," wrote Mr. Romero.

Fourth Amendment forgotten?

"Too many people think the Patriot Act doesn't affect them, and that if it does, it doesn't matter," says former Rep. Bob Barr (R) of Georgia, who is now urging revisions in the law. "It severs the very foundation of the Fourth Amendment to say that government can invade a person's privacy and gather information against them without having a sound basis for suspecting that they've done something wrong," he says.

On Wednesday, lawmakers in both the House and Senate introduced bills to rein in the law. The Security and Freedom Enhancement (SAFE) act raises the bar for secret searches and scales back the government's authority to seize personal information without judicial review. Backers range from the ACLU to Gun Owners of America.